From: Jr G. <goo...@gm...> - 2007-08-24 08:23:42
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Dear All, I want to collect L1 cache misses, L2 cache misses and TLB misses. But I don't know which events to use. Can you help me? The events in oprofile's document (ICACHE_MISSES, DATA_CACHE_ACCESSES, DATA_CACHE_MISSES, DATA_CACHE_REFILLS_FROM_L2) seems do not differentiate L1 and L2 cache. Another question about the counter field for events: count The counter reset value, e.g. 100000 if I set the count of CPU_CLK_UNHALTED to 10000, and oprofile tells CPU_CLK_UNHALTED 1000 samples, does this mean the total cpu cycles used is 1000*10000=10^7? Thank you all! . |
From: William C. <wc...@re...> - 2007-08-24 14:53:44
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Jr GooGirl wrote: > Dear All, > > I want to collect L1 cache misses, L2 cache misses and TLB misses. But I > don't know which events to use. Can you help me? > The events in oprofile's document (ICACHE_MISSES, DATA_CACHE_ACCESSES, > DATA_CACHE_MISSES, DATA_CACHE_REFILLS_FROM_L2) seems do not > differentiate L1 and L2 cache. Hi, You need to state which processor you are running the experiments on. The performance monitoring hardware is very processor implementation specific. Knowing which processor would allow people on the mailing list to make specific suggestions on what to measure. You might look at the following text document for some suggestions on what to measure. http://people.redhat.com/wcohen/FedoraCore6OProfileTutorial.txt > > Another question about the counter field for events: > |count| The counter reset value, e.g. 100000 > > if I set the count of CPU_CLK_UNHALTED to 10000, and oprofile tells > CPU_CLK_UNHALTED 1000 samples, does this mean the total cpu cycles used > is 1000*10000=10^7? The counter counts events and causes a sample each time that number of events are counted. There is not multiplication of what you select and what oprofile selects. Thus, if on the opcontrol line you select the counter to 1000000 events will be sampled every 1000000. For common events like clock cycles you probably want samples collectection intervals to be in the hundred thousands to million range. -Will |